I would think you'd want to be in the room with the piano so that you could hear what a subtle tweak in MIDI velocity amounted to acoustically when the hammer hits the string.
The idea that they may edit on site seems good.
The way velocity layers on a sample set are mapped is discrete and manipulated to give the impression of wide ranging dynamics.
The robotics on a player piano will have it's own unique response curve... a lot like the way each human player interacts with each piano action a bit differently.
I got to record a performance on a Hamburg Steinway last week. It was previously selected and owned by Aaron Copland, and it is maintained by the current owner as if it is the jewel of the fleet. Goodness, it was nice to be in that room for those few hours.
Anyways, my head's still trying to get straight with the idea that a song can have a 50 second intro... in my mind a 50 second piece is a song. :-)
all the best,
mike